U.S. Pat. No. 2,419,305 teaches multiple engine power plants, and particularly to a power plant which comprises a number of high production, small horsepower engines assembled on a common crankcase. The engine clocks are secured to the case by hold-down bolts and the engines are arranged in radial circumferentially spaced relation with respect to the longitudinal central axis of the case. The spacing being such that the engines and their accessories are readily accessible.
Patent application no. GB395423 teaches a system having a number of radial-cylinder-stationary or revolving-engines driving a common propeller shaft that are mounted between endplates, which are connected by a tube through which the shaft passes. Each engine is held on to the plates by bolts passing through a collar and a belt. The drive from the engine crank shafts to the propeller shaft is by chain spur or bevel gear; a clutch may be interposed in each transmission. In all cases, irrespective of the arrangement of the elementary engines amongst themselves the transmission of the power of these engines to the common shaft is effected by transmission members, chain wheels or gear pinions, separate for each elementary engine.
Patent application no. DE10315833 teaches a frictional connection between crankshafts for a slider crank drive and drive or driven mechanism through a device incorporating all rigid shaft axes by means of in-phase cranks.